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