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