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