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