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