If you can use the NPN transistor, just use the circuit on the right. If you don't have the NPN transistor, you'll need two transistors to pull off the circuit on the left - one to level shift from 5v to 12v plus the rest of the circuit on the left side.

If you don't need 12v, and can live with 5v, then just use whichever circuit you want, depending on what type of transistor you have.

If you can't live with the inverse signal polarity for turning on the LED, you're going to have to either get the NPN transistor, or rethink the problem...

you have options here...

-Dave