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