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