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