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