On a deload, depending on whom you ask, Jim Wendler wants you to reduce volume (on 531) by 60%; others say shorten the sets and reps; still others say do some light cardio. The point of the deload is to give both the CNS and the body a rest by reducing what you normally do.
I say do 60% of short sets and less reps. Continue to do cardio, because you're working two totally different physiological systems. Plus there are some theories that cardio is good for you and can help progress, as well as cutting inflammation.