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