Congrats sir.
Sounds like your son worked his tookus off.
When my 2 boys graduated times were tight. Yet I had been able to pay for their tuition, books etc as they went. So in both cases we went to a nice fish house for supper and I presented them with a nice custom made pen & pencil set with their name and the date they graduated. The box and items inside have their college logo on it as well.
Both of my boys drove better vehicles than me as I'd made sure they had reliable vehicles.
So in our house we kinda treated it like a normal day other than the fact that neither had to go to school tomorrow.
My oldest worked a full time job while he went. The youngest worked part time. In both cases they took graduation day off. lol.
I suppose at my home it was not the norm to not make a huge deal out of it. Especially since they were the first to finish college.
Looking back I kinda regret that we didn't do more. But looking at things a few years later, now they have their own place, and neither works in their field they went to school for so...eh, it is what it is.