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)(11,17)(12,21)(13,16)(14,22)(15,19)(18,20)(23,24)(25,26,30,33)(27,34,37,40)(28,32,29,38)(31,36,39,35)(1,3,5,4)(2,6,8,7)(9,11,13,19)(10,15,16,17)(12,18,22,23)(14,20,21,24)(27,35)(28,29)(31,34)(32,38)(36,37)(39,40)(1,3,5,4)(2,7,8,6)(9,12,21,10,13,22,14,16)(11,18,24,15,19,23,20,17)(25,27,29,35,30,37,28,36)(26,31,32,34,33,39,38,40)(1,4,5,3)(2,7,8,6)(10,16)(11,19)(12,22)(20,24)(25,28,30,29)(26,32,33,38)(27,36,37,35)(31,34,39,40)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.