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