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