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