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