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)(11,12)(13,15)(14,16)(17,18,22,21)(19,24,20,23)(25,26,29,32)(27,33,35,30)(28,36,37,31)(34,38,40,39)(1,3,5,4)(2,6,7,8)(9,11)(10,14)(12,15)(13,16)(17,19,22,20)(18,23,21,24)(28,37)(31,36)(34,40)(38,39)(3,4)(6,8)(11,16)(12,14)(17,19,22,20)(18,24,21,23)(25,27,29,35)(26,30,32,33)(28,34,37,40)(31,38,36,39)(1,2)(3,6)(4,8)(5,7)(9,10)(11,14)(12,16)(13,15)(17,20,22,19)(18,23,21,24)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,37)(38,40)(1,4,5,3)(2,6,7,8)(9,12,13,14)(10,11,15,16)(17,21,22,18)(19,24,20,23)(25,28)(26,31)(27,34)(29,37)(30,38)(32,36)(33,39)(35,40)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.