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