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