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