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