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