One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,12)(8,17)(9,13)(10,18)(11,14)(15,20)(16,19)(24,32)(26,34)(28,33)(31,36) involution — undirected(1,2,4,3)(5,7,11,16)(6,12,14,19)(8,9,15,10)(13,20,18,17)(21,22)(23,29)(24,33)(25,27)(26,31)(28,32)(30,35)(34,36)(5,8,10,7,11,15,9,16)(6,12,13,17,14,19,18,20)(21,23)(22,26,27,34)(24,31)(25,30)(28,29,33,35)(32,36)(1,3,4,2)(5,9,11,10)(6,13,14,18)(7,8,16,15)(12,17,19,20)(23,30)(26,34)(29,35)(31,36)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.