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