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