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