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