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