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