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)(15,19)(16,20)(17,18)(22,26)(23,29)(24,32)(35,36) involution — undirected(8,12)(10,11)(14,18)(15,20)(21,22,25,26)(23,30,29,27)(24,33,32,28)(31,35,34,36)(6,7)(10,11)(15,20)(16,19)(21,23,25,29)(22,27,26,30)(24,34,32,31)(28,36,33,35)(1,2)(3,4)(5,7,9,6)(8,11,12,10)(13,15,17,20)(14,19,18,16)(21,22)(23,27)(24,28)(25,26)(29,30)(31,35)(32,33)(34,36)(5,8)(6,10)(7,11)(9,12)(13,16,17,19)(14,20,18,15)(21,24,25,32)(22,28,26,33)(23,31,29,34)(27,35,30,36)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.