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