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