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