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