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