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