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