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