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