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