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