If your cat is pulling on the cables by way of attention - then the best way to divert this behaviour is to ignore it. Your kitty is smart and has learned that by doing so - she/he receives the attention demanded. By not responding (talking, petting, picking up or even shouting) eventually, kitty will become bored with the action because there is no reward anymore...so therefore, no reason to continue.
This just may take a few times for the association to be made.
However, if this behaviour is more then just for the attention being received, there are several reasons a cat may engage in chewing inappropriate items. These include; boredom, stress, separation anxiety or even OCD (obsessive compulsive disorder). There may be a medical (such as nutritional deficiency) or a dental issue involved. Please consider checking with your veterinarian, if you feel any of these concerns to be related to this behaviour.
* If your cat chews plastic. Please note: some plastic bags contain lubricating chemicals called slip agents that prevent them from sticking together. These agents sometimes are rendered from animal fat. A cat's keen sense of smell can often detect this enticing aroma.
In the meantime, provide plenty of chewy toys for your cat to entice his chewing desires. There are also cord/wire protectors on the market that can be easily applied over top of the existing cords that may help.