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