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