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