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