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