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