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