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)(13,14,17,19)(15,23,24,20)(16,21,25,27)(18,22,26,28)(5,7)(6,9)(8,12)(10,11)(14,19)(15,16)(18,26)(20,21)(23,27)(24,25) involution — undirected(1,2,3,4)(13,15,18,16,17,24,26,25)(14,20,22,27,19,23,28,21)(6,10)(9,11)(14,19)(15,24)(16,25)(22,28) involution — undirected(7,12)(9,11)(13,16,18,24,17,25,26,15)(14,21,22,20,19,27,28,23)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.