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