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