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