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