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