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