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