I have had my pump for almost 10 years and it is not covered. It sees plenty of sun. You can certainly use one of those pump covers but you must make sure the pump has good airflow and the intake fan is not obstructed in any way or else you risk burning out your pump motor.
Also, check the dimensions of that cover. Many of them are designed for simple single speed pumps which have small motor bodies. VSPs are typically taller and wider than a standard pump motor and so the cover may not fit.