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