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