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