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