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