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