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