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