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