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