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