The cables are (mostly) hidden in the frame of the desk.
2015 Midrange GTX 970: My first build
This is the first PC I ever build. I built it around February 2015 and at the time this PC was a beast for what I was used to with an I5 4460 pared with a MSI GTX 970 Gaming 4G.
Please don't judge the cable management I know it's terible, if you can even see it on the picture. I put the cables in a position where I can't see them through the side pannel window so aslong as I don't open the case it looks pretty clean.