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