Here is the insert for all those who wanted it.
Along with the original, I've included one with no numbers, and a template file for designing your own inserts. On the template, the light gray hexagonal area is the live area. Anything outside the black outline or inside the black circles will be covered by the buttons or the borders of the joystick handle. So make sure to place any text or graphics that you want visible inside the light gray area.
Note: the correct size is embedded in the files, so they should come out the correct size when printed.
Hope you like them.
Update: Added one with more Tron-like numbers.