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