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