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