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