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