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