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