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