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