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)(13,14,17,19,18,22,16,21)(15,20,23,26,25,28,24,27)(1,2,3,4)(5,7)(6,9)(8,10)(11,12)(14,19)(16,17)(20,26)(21,22)(23,24)(27,28)(5,6)(7,9)(8,12)(10,11)(13,15)(14,20)(16,24)(17,23)(18,25)(19,26)(21,27)(22,28) involution — undirected(6,7)(10,12)(13,16,18,17)(14,21,22,19)(15,23,25,24)(20,26,28,27)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.