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