I say a cute side part slicked and pulled back into a low faux bun. You can use your own hair or make a trip to the BSS and get some marley hair and fashion a bun to pin over your own hair. Co wash and seal your hair the night before, part your hair, smooth it back with a smoothing brush (you can add more oil) and pull into a low ponytail. You can pin the ends under and tie a scarf on and go to bed. You'll wake up with a nicely shaped bun and smooth hair ready for graduation.
Here it is when I did it with shorter hair. Ignore my neck fuzz lol