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