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