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