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