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