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)(13,14,17,21)(15,23,25,19)(16,24,27,20)(18,22,28,26)(6,10)(11,12)(13,15,17,25)(14,19,21,23)(16,26,27,22)(18,24,28,20)(2,4)(15,24)(16,19)(18,28)(20,25)(22,26)(23,27) involution — undirected(5,7,9,8)(6,11,10,12)(13,16)(14,20)(15,22)(17,27)(18,23)(19,28)(21,24)(25,26)(5,8,9,7)(6,12,10,11)(15,20)(16,23)(18,28)(19,27)(22,26)(24,25)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.