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