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