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