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