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