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