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