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