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