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