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