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