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