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