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