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