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