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