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