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