You Do Need power plug adapter while traveling from Saudi Arabia to Cocos (Keeling) Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Cocos (Keeling) Islands is I and in Saudi Arabia is G. This is how they look like.

Saudi Arabia

In Saudi Arabia, outlets of type G are in use.

Type G

Cocos (Keeling) Islands

In Cocos (Keeling) Islands, outlets of type I are in use.

Type I