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