Hey, I don't think there is such a thing. I've only seen serial to XTS.
In fact, I'm surprised that there are ribless cables, but even those
are connected to serial ports. I'm not sure if you're aware, but any
computer new enough (or fast enough) to have a USB port is likely to be
way to fast for programming those radios.

But if I'm wrong, please be sure to forward the schematics for the USB
to XTS programming cable.

You might look at batlabs.com as well. Most of the resources I ever
need are there.