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