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