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