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