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