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