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