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