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