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