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