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