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