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