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