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