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