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