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