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