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