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