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)(15,21)(16,19)(17,20)(18,24)(22,27)(23,26)(25,28) involution — undirected(6,9)(7,11)(13,15)(14,18)(16,24)(17,22)(19,21)(20,26)(23,25)(27,28) involution — undirected(2,4)(15,22)(17,25)(18,26)(20,28)(21,27)(23,24) involution — undirected(6,9)(10,12)(14,19)(18,21)(20,28)(26,27) involution — undirected(5,7,8,11)(6,10,9,12)(15,23)(17,25)(18,27)(20,28)(21,26)(22,24)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.