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