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