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