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