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