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