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