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