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