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