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