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