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