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