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