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