So you have the premutation on defined as,

This is an element of a finite group thus it has an order. We need to find the smallest positive integer such that is the identity premutation.

Observe the following,

This show that is the order.

To express it as a product of disjoint cycles we find the orbits of which are,

Thus,

(Note although the binary operation on the premutation group is not commutative here it is and I could have expressed the product the other way aroung because the cycles are disjoint).