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