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)(13,14,18,22)(15,23,21,17)(16,20,26,19)(24,27,25,28)(5,7)(6,9)(8,11)(10,12)(13,15,17,14,18,21,23,22)(16,25,27,20,26,24,28,19)(1,2,3,4)(6,10)(7,11)(13,16)(14,19)(15,24)(17,27)(18,26)(20,22)(21,25)(23,28)(7,11)(9,12)(13,16)(14,20)(15,25)(17,27)(18,26)(19,22)(21,24)(23,28) involution — undirected(16,26)(19,20)(24,25)(27,28) 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.