Could you use lenses that fit a Chinon CS-4 on a Canon EOS 750D?
With an M42 → EF adapter you could. But there would be significant compromises. There would be no autofocus. There would be no auto exposure. You'd need to select both shutter duration and ISO manually on the camera and aperture manually on the lens. Since the camera would have no way of communicating with the lens, it would not know what aperture the lens is wide open, nor what aperture it is set to. Some higher end Canon bodies would allow you to manually tell the camera the aperture selected on the lens, but without that, you're not going to get accurate exposure metering. So you'd probably also need an external light meter.
Four of the five lenses shown in the photos are 50mm or 58mm. You can get an EF 50mm f/1.8 STM that will preserve the camera's ability to autofocus and auto expose for a little over $100. That's not a LOT more than a high quality M42 → EOS adapter. And don't even think about getting a decent light meter for anywhere near the remainder after you buy an adapter.
So the question is mostly would it be worth the hassle of full manual exposure without accurate metering and manual focus to use the 135mm f/3.5 with an adapter?
Maybe it would, but there are also some pretty good copies of the older Canon EF 135mm f2.8 (with soft focus mechanism) still floating around for less than $200. In return you get AF, communication between the camera and body for exposure purposes, and a pretty good lens. The Soft Focus feature can be adjusted to "None" or to a weaker and stronger effect. It's very handy to have for several kinds of portraiture.