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