You can take steps to make your property less inviting to coyotes. For example, don’t leave food, even cat food, outdoors. Fencing your yard may help, but it won’t solve the problem since cats tend to wander and coyotes have been known to jump fences. Lights on motion detectors may deter coyotes as well.
A coyote vest for cats will provide a physical barrier between a coyote’s teeth and your cat’s body. Some coyote vests confuse predators with visual deterrents as well.