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