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