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