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