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