One vertex per element, one color per generator, with an edge from x to x·s.
(2,3)(5,6)(7,11)(8,17)(9,19)(10,15)(12,18)(13,16)(14,20) involution — undirected(1,2,4,3)(5,7,10,12)(6,11,15,18)(8,14,13,19)(9,17,20,16)(5,8)(6,12)(7,15)(9,11)(10,13)(14,16)(17,19)(18,20) involution — undirected(5,7)(6,13)(8,15)(9,17)(10,12)(11,19)(14,18)(16,20) involution — undirected(1,3,4,2)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.