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