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