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