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