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