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