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