One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(4,6)(7,8,12,15)(9,10,13,18)(11,14,20,22)(16,17,19,21)(23,24,29,28)(25,32,26,30)(27,35,36,31)(33,37,34,38)(7,9,12,13)(8,10,15,18)(11,19,20,16)(14,21,22,17)(23,25,29,26)(24,30,28,32)(27,33,36,34)(31,37,35,38)(3,4,5,6)(7,9)(8,10)(11,16)(12,13)(14,17)(15,18)(19,20)(21,22)(23,26,29,25)(24,30,28,32)(27,33,36,34)(31,38,35,37)(7,10)(8,13)(9,15)(11,17)(12,18)(14,19)(16,22)(20,21)(23,27,29,36)(24,31,28,35)(25,33,26,34)(30,37,32,38)(7,11,12,20)(8,14,15,22)(9,16,13,19)(10,17,18,21)(23,28,29,24)(25,30,26,32)(27,35,36,31)(33,37,34,38)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.