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