One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,5)(6,8)(9,10,14,15,12,11,13,16)(17,18,21,25,20,24,29,23)(19,26,28,32,27,22,30,31)(2,5)(6,7)(9,11,13,15,12,10,14,16)(17,19,21,28,20,27,29,30)(18,22,25,31,24,26,23,32)(10,15)(11,16)(13,14)(18,23)(19,27)(21,29)(22,31)(24,25)(26,32) involution — undirected(1,3,4,8)(2,6,5,7)(10,11)(15,16)(18,24)(19,27)(23,25)(28,30)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.