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