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