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