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