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