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