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