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