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