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