One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,5,7,8)(9,10,12,15)(11,16,13,14)(17,18,21,24)(19,25,27,32)(20,29,26,23)(22,30,31,28)(1,3)(2,5)(4,7)(6,8)(9,11,12,13)(10,14,15,16)(17,19,26,30,21,27,20,28)(18,22,29,32,24,31,23,25)(3,7)(5,8)(10,14)(11,13)(15,16)(19,27)(22,31)(25,32)(28,30) involution — undirected(10,15)(14,16)(17,19,26,30,21,27,20,28)(18,22,29,32,24,31,23,25)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.