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