Keywords: Symmetric group 4; Cayley graph 1,5,21 (Nauru Petersen); matrices.svg Cayley graph of S<sub>4</sub> generated by blue 12 green 13 red 14 This is a Nauru graph compare http //11011110 livejournal com/124705 html The many faces of the Nauru graph by 0xDE own v fl mate2code 300px300px Nauru graph 4x4 permutation matrix |