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