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