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