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)(11,12)(13,18)(14,15)(16,17)(19,20)(21,24)(22,23)(25,26,29,32)(27,30,33,37)(28,31,36,35)(34,38,39,40)(2,3)(6,7)(10,15)(11,17)(18,23)(19,21)(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)(12,16)(18,23)(20,24)(27,33)(30,37)(34,39)(38,40)(1,3,5,2)(4,7,8,6)(9,11,14,17)(10,16,15,12)(13,21,22,19)(18,20,23,24)(25,26)(27,30)(28,35)(29,32)(31,36)(33,37)(34,40)(38,39)(1,4)(2,6)(3,7)(5,8)(9,12,14,16)(10,17,15,11)(13,20,22,24)(18,21,23,19)(25,27)(26,30)(28,34)(29,33)(31,38)(32,37)(35,40)(36,39)(9,13)(10,18)(11,19)(12,20)(14,22)(15,23)(16,24)(17,21)(25,28)(26,31)(27,34)(29,36)(30,38)(32,35)(33,39)(37,40) 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.