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