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)(27,33)(28,30)(29,36)(31,34)(32,37)(35,38)(39,40)(2,3)(6,7)(10,13)(14,16)(17,19,21,18)(20,23,24,22)(26,28)(27,34)(32,36)(35,40)(1,2,5,3)(4,6,8,7)(9,10)(11,14)(12,13)(15,16)(25,27)(26,31)(28,33)(29,35)(30,34)(32,38)(36,39)(37,40)(1,3,5,2)(4,7,8,6)(9,11,12,15)(10,14,13,16)(17,20,21,24)(18,22,19,23)(25,28,30,26)(27,33,34,31)(29,32,37,36)(35,38,40,39)(1,4)(2,6)(3,7)(5,8)(25,29,30,37)(26,32,28,36)(27,35,34,40)(31,38,33,39)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.