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