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