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