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