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