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