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