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