This isn't exactly a wiring diagram, but a how to, on wiring your fpv set up to more easily incorporate the eagle tree system...
This is based on the inexpensive FPV system from HobbyKing, but it should be pretty universal.
you have a camera.
from the camera runs a wire with a plug, that meets the transmitter, that has a plug and power lead.
cut the connection plugs off both the tx wiring, and the camera.
take one of these...
cut it in half, solder one half to the tx wiring
Now, for the camera. You have three wires. I soldered on the female end of a servo extension. (that's the same plug as would be on the servo itself, in fact, you could use a dead servo's lead, but you'll need a make end for this anyway.)
Next you need to make a "jumper." I took the other half of the charge lead, and I soldered it up to match the leads from the servo, in addition to that, I soldered in a JST battery connection. Ignore the blue lead, it is the audio feed. Unless you plan to hook up a mic. Then you can take another servo extension, and wire it in, matching the white on it, to the blue, then adding the red to red, black to black.
So, now I have my Tx, with the male end of the charge lead.
A jumper with a male half of a servo extension, a male JST (you can use any plug you want, to match what your battery has.) lead, and the female end (yeah, I could have done it the other way around, and have it all male ends on here, sue me...) of the charge lead.
Last, I have my camera with the female servo plug.
This is important, because you need to plug the camera into the OSD device, then you need to route out from there, to the vTx.
It's that simple.