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