What model year is this bike? I didn't know Cannondale ever sold a disc version of the CAADX with quick release.
You will likely need a custom wheelset. No one is selling off-the-rack disc wheels with quick release these days. I agree with Mstateglfr that Prowheelbuilder.com is a good option for this.
I'd target something like:
Bitex MTF hubs (compatible with QR 100mm and 135mm spacing)
DT Swiss R470 rims
28 CX-Ray spokes
$556.52/1620 grams
There are lots of different rim options that could work, so there might be a better option than the DT Swiss R470.