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