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