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