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)(12,14)(13,15)(17,18,21,19)(20,23,24,22)(25,26,30,31)(27,32,33,28)(29,34,38,39)(35,37,40,36)(2,4)(6,7)(9,11)(10,15)(12,16)(13,14)(17,18,21,19)(20,22,24,23)(26,31)(27,33)(34,39)(35,40)(1,3)(2,6)(4,7)(5,8)(9,10,14,12)(11,16,13,15)(17,19,21,18)(20,23,24,22)(25,27)(26,32)(28,31)(29,35)(30,33)(34,37)(36,39)(38,40)(1,3)(2,7)(4,6)(5,8)(9,12,14,10)(11,16,13,15)(17,20)(18,22)(19,23)(21,24)(25,28,30,32)(26,33,31,27)(29,37,38,36)(34,35,39,40)(1,4,5,2)(3,7,8,6)(9,13,14,11)(10,15,12,16)(25,29)(26,34)(27,35)(28,36)(30,38)(31,39)(32,37)(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.