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