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