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