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)(11,15)(12,20)(13,14)(16,22)(17,19)(18,24)(21,23)(25,26,31,35)(27,36,40,32)(28,33,38,30)(29,34,37,39)(1,2,5,4)(3,6,8,7)(9,10)(11,17)(12,16)(13,14)(15,19)(18,24)(20,22)(21,23)(25,27)(26,32)(28,37)(29,38)(30,39)(31,40)(33,34)(35,36)(1,3)(2,6)(4,7)(5,8)(10,14)(15,17)(16,20)(23,24)(25,28,31,38)(26,33,35,30)(27,37,40,29)(32,34,36,39)(1,3,5,8)(2,6,4,7)(9,10)(11,17)(12,16)(13,14)(15,19)(18,24)(20,22)(21,23)(25,28)(26,30)(27,37)(29,40)(31,38)(32,39)(33,35)(34,36)(1,3)(2,7)(4,6)(5,8)(9,11,13,19)(10,15,14,17)(12,21,22,18)(16,24,20,23)(25,29,31,37)(26,34,35,39)(27,38,40,28)(30,32,33,36)(1,4,5,2)(3,7,8,6)(9,12,13,22)(10,16,14,20)(11,18,19,21)(15,23,17,24)(25,30)(26,28)(27,39)(29,36)(31,33)(32,37)(34,40)(35,38)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.