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