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)(15,24)(17,20)(21,22)(23,27)(26,28) involution — undirected(5,7)(6,9)(8,12)(10,11)(13,14,20,27,18,23,17,19)(15,21,16,22,24,28,25,26)(2,4)(7,12)(9,10)(13,15)(14,21)(16,20)(17,25)(18,24)(19,26)(22,27)(23,28) involution — undirected(5,7)(6,10)(8,12)(9,11)(13,16,18,25)(14,22,23,26)(15,20,24,17)(19,21,27,28)(7,12)(9,10)(14,23)(15,24)(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.