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