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