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