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