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