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