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