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)(11,19)(12,18)(13,16)(14,20)(15,17)(21,24)(22,23)(25,26,29,30)(27,33,35,31)(28,32,36,37)(34,39,40,38)(2,3)(6,7)(9,11,15,13)(10,16,17,19)(12,23,20,21)(14,22,18,24)(26,30)(31,33)(32,37)(38,39)(1,3,5,2)(4,7,8,6)(10,17)(12,20)(16,19)(21,23)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(1,4,5,8)(2,6,3,7)(9,12)(10,18)(11,21)(13,23)(14,17)(15,20)(16,22)(19,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(9,13,15,11)(10,19,17,16)(12,23,20,21)(14,22,18,24)(25,27,29,35)(26,31,30,33)(28,34,36,40)(32,38,37,39)(9,14,15,18)(10,20,17,12)(11,22,13,24)(16,21,19,23)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)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.