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