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