One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,15)(12,16)(13,17)(14,18)(19,23)(20,22)(21,24)(28,36)(30,39)(32,37)(34,38) involution — undirected(2,5)(6,8)(9,11,14,20)(10,15,18,22)(12,21,13,19)(16,24,17,23)(25,26)(27,33)(28,37)(29,31)(30,34)(32,36)(35,40)(38,39)(10,16)(11,19)(12,13)(17,18)(20,21)(23,24)(25,27,29,35)(26,30,31,39)(28,38,36,34)(32,40,37,33)(1,3,4,7)(2,6,5,8)(11,20)(15,22)(19,21)(23,24)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.