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