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