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