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