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