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)(15,26)(16,22)(17,23)(18,24)(19,28)(20,25)(21,27) involution — undirected(1,2)(3,4)(13,15)(14,21)(16,19)(17,20)(18,27)(22,25)(23,24)(26,28) involution — undirected(2,4)(6,9)(10,12)(13,16,20,27)(14,22,25,21)(15,18,17,19)(23,28,26,24)(2,4)(13,17,20,15)(14,23,25,26)(16,18,27,19)(21,28,22,24)(5,7,8,11)(6,10,9,12)(13,18,20,19)(14,24,25,28)(15,27,17,16)(21,23,22,26)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.