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