Thanks for contacting us here on the forums. The only way the Slingbox M1 would be able to get connected to a cable box is with component or composite cables, on its own. I looked up the back of that model, and it looks like you only have yellow, white, and red. The cable that came with the Slingbox might not have a yellow, but you can use one of the component video cables as a replacement. If the cable box has an HDMI port, you can find a HDMI to component adapters that would work. We have a link for one off our website that might help you out if that is the case.
Hope that helps.