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