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