So you're 6' tall, 270 pounds, running a 5.1-ish 40-yard dash.
What position are you hoping to get noticed for? Nose guard, I am guessing? Either that or you're a former LB/FB that has overgrown your position a little bit? Obviously this matters. If you think you're going to play on the defensive line, it will not do much good for you to show up weighing 250 (even if that nudges your 40 from 5.1 back down into 4.9 or 4.8 range). If you're hoping to catch on as a linebacker or a fullback, then you might be better suited showing up around 245-255 with a faster 40. To be honest, I think the kind of training you've been doing recently matters, too; are you still in pretty good shape? Have you been lifting or sprinting at all?
Regardless, the training you should do at this point seems pretty obvious. Get onto any good football lifting program, add some sled drags / hill sprints / etc, do some work on your vertical leap as well (that's usually tested, too; even if you're a lineman, a good vertical is a sign of all around athleticism), same goes for your broad jump...the only thing I'm not sure of is whether you should ALSO prioritize fat loss (if you're expecting to play LB and need to show up more like 250 pounds running a 4.7-ish 40) or just get as strong and fast as possible (if you're expecting to play DL, you probably need to keep your current bodyweight).