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