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