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