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