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