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