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