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