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