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