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