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