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