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