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