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