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