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