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