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