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