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