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)(11,14)(12,15)(13,17)(16,21)(18,22)(19,24)(20,23)(25,26,30,34)(27,35,37,39)(28,33,29,32)(31,36,40,38)(2,5)(6,7)(9,11,13,19)(10,14,17,24)(12,20,21,18)(15,23,16,22)(27,36)(28,29)(31,39)(32,33)(35,40)(37,38)(10,15)(12,21)(14,22)(16,17)(18,20)(23,24)(25,27,30,37)(26,31,34,40)(28,36,29,38)(32,39,33,35)(1,3,4,8)(2,6,5,7)(27,37)(31,40)(35,39)(36,38)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.