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