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