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