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