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