there is some methods of calming and taming snake, the first one is persist with handling. if you handle him daily he will likely to know your scent as undangerous beings and calm down.
also you can try the shirt method. use a shirt for a day long do everything with it (go out and have a run) and so that shirt is full of your scent. put it in the cali tank, and he will see your scent (and shirt) as safe things. put it there for 3 days or so.
and of course, most young colubrid snakes are like that, they're easily scared, but i think it will dissapear when they're adult.
hope this helps mate