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