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