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