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