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