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