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