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