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