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