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