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