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