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