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