First of all, great job on wanting to be responsible with that money, a lot of college students your age wouldn't!
Personally, I think the first thing you should use it for is paying off school debt. Having that school debt taken care of will be a huge weight taken off you, and will allow you to focus on your life and career with a more clear mind.
You should definitely stash a chunk of it as an emergency fund, like 3-4 months rent or something. As for the rest of it, definitely invest it. Investing is a whole other thing on it's own so you'll have to research that yourself, but I recommend investing in low cost index funds from somewhere like vanguard or Shwab. Once again, read up on all this. There are a lot of people way smarter than I am who wrote books and articles on this stuff.
If starting a business is something you really want to do, you can use it for that, but make sure you have a well thought out business model if you do that. Don't just dump your money into something you're not sure of.
Best of luck!!
EDIT: Here are a couple books that I recommend you to check out!
I will make you rich by Ramit Sethi
The little Book of common sense investing by John Bogle
"I will teach you to be rich" by Ramit Sethi is really good.
Congrats to you too then! Being debt free will change your perception. You can do it!
Here are some of the best books I can recommend:
I Will Teach You To Be Rich
Your Money Or Your Life
The Little Book Of Common Sense Investing
FYI, /u/ReasonableFeed, your question (and a bunch of the shittier responses you got) was just featured in an email from the I Will Teach You To Be Rich guy. Just thought you might find it interesting so I pasted it below. I think he's pretty spot on. Don't cut out a vacation--you'll just increase the risk of burnout. You're saving 40k a year, paying your parents 10k a year, and paying down 20k in student loans. You're doing fine (and I promise you that a lot of your peers aren't spending that last 30k which might make up a big chunk of your perceived differences). Heck, you probably have peers who aren't even contributing to their 401k.
Meal prepping is an option, but honestly for you it should be more about a lifestyle/health choice than money. You'll probably eat healthier if you do it (you're menu is already set, so you're not going to end up with that cheeseburger and fries for lunch on a stressful day), but it will take up some of your limited free time. You can keep your 401k high...once you max it out, just re-route those contributions into a backdoor Roth IRA. Also, not sure if you factored this in to your monthly income, but your actual paycheck should grow larger by the end of the year as you hit the 401k cap and roll out of social security tax eligibility (above ~128k) and stop paying that extra 6.2% tax.
One thing I’ve learned as I’ve made money, grown my business, etc. is how quickly I outgrow advice on the internet.
It turns out that the vast majority of financial advice on the internet is geared towards the lowest common denominator: “Save money by packing your own lunch!”
Interestingly, as I moved past the basics, I realized something that nobody really likes to talk about: The best advice in areas like finance, power, and business all happen behind closed doors.
Here’s one example from Reddit. Here’s a consultant earning $204,000/year who asks: “I'm sharing my finances below — am I doing something wrong? Or is this normal and I just had misaligned expectations?”
Some of the advice is solid, but suddenly the haters come out:
“You are spending too much on food, $750/mo, really? I wouldn't envision anymore than $350-400/mo, do you eat out 24/7 or something.”
“Jesus Christ, dude. I know consulting is full of type A never-happy keeping-up-with-the-joneses insecure overachievers but a big dose of perspective wouldn't go amiss.”
“You are in the top 0.04\% of richest people on the planet. You are not fucking poor. Some (most) people would kill to be able to sock away 40k a year into savings. Your budget is wrong and you haven't calculated your taxes right but you are doing incredibly well, work for one of the most prestigious companies on the planet and are almost unbelievably privileged.”
Anyone earning six figures sees a post like this and thinks, “The internet is not for people like me to ask for advice,” and quietly backs away from the screen.
Yes, this guy makes more than the average person (which he acknowledges). But even high earners have questions. But if you listen to the advice on the internet, this is outrageous and elitist. Wrong.
I refuse to give advice that only addresses people in deep debt. That’s why I wrote a detailed step-by-step post on how I spend $50,000/year on luxury services — which a surprising number of people do, but few will write about publicly.
If you’re in debt, there’s plenty of advice out there for you. Follow my advice and you’ll know your exact debt payoff date.
But what about the rest of us? The people who moved beyond debt, who want more advanced advice about money and psychology and earning power and how to spend it?
It’s OK to graduate beyond basic frugality advice. In fact, you should. If you’re still reading the same “tips” you read 10 years ago, something is wrong.
It’s OK to want more advanced advice that suits your needs now.
And it’s OK to know there are other people out there like you.
Books that helped me out when I first started:
Read this book. It puts everything in very simple terms. https://toptalkedbooks.com/amzn/0761147489
The One Page Financial Plan  as kokonotu points out is also a good one.
Further more, I'd recommend thinking about what you want to achieve with money. Ramit will tell you to enjoy life and save enough for later, I personally think the amount of money we (can) earn as software engineers can be used to buy a lot more 'free time' than most people think, allowing us to 'retire' (travel the world programming, building open source software, or whatever you like...) way earlier than most people. If you're interested in that kind of think you could have a look into Mr Money Mustache's blog  for instance. (Disclaimer: Some people might think he's a bit extreme, if you're that kind of person just try to pick up some of the good parts/habits and you'll be way ahead of the curve.)
I got a lot more mileage than I thought I would out of books like I Will Teach You To Be Rich by Ramit Sethi(http://www.amazon.com/Will-Teach-You-Be-Rich/dp/0761147489/r...). It rubs some people the wrong way, but it has some really good points about automating finances, and just handling companies via some social engineering.
Some of the things I think a bunch of people working day jobs are the insane benefits their companies offer. Make sure both your and your significant other are maximizing their 401k benefit(at least to kick in the employee matching and more if you can afford it).
The savings accounts should just keep compounding on each other. Possibly toss some other money into a Roth or into the stock market. Also have a rainy day/emergency fund for when the roof leaks and other unforeseen circumstances.
If you have a side project, that money should be coming out of your personal spending money. It should be thought of as your hobby and not impede on the family as a whole(this is for day jobbers).
Obviously finances get a bit rougher if there is no day job and it is just startups, it gets more difficult. One of the plans I had envisioned was to have an account setup and once it reached a certain percentage of drainage(aka burn rate for funded companies) that was agreed upon in the family, then there would be a meeting to discuss hanging it up and looking for a new day job to refill the fund to try again.
If you luck out and get funded and/or someone buys a project, that money should go first to replenish the project fund and then go into emergency, savings, and a little left over to celebrate(vacation, new back door, etc).
(As a disclaimer, I own a copy of said book, and I think it's good.)