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