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