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