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