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