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