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