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