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