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