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