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