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