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