the 3 isometry classes of irreducible [8,4,4]_3 codes are:

code no       1:
================
1 1 1 1 2 0 0 0
2 1 1 0 0 2 0 0
2 1 0 1 0 0 2 0
2 0 1 1 0 0 0 2
the automorphism group has order 192
and is strongly generated by the following 5 elements:
(
1 0 0 0 
0 1 0 0 
0 0 1 0 
2 2 2 2 
, 
2 0 0 0 
0 2 0 0 
0 0 0 2 
0 0 2 0 
, 
2 0 0 0 
0 0 2 0 
0 2 0 0 
1 1 1 1 
, 
1 2 0 2 
0 0 1 0 
2 2 2 2 
0 0 0 2 
, 
0 2 0 0 
1 2 0 2 
2 0 0 0 
1 2 2 0 
)
acting on the columns of the generator matrix as follows (in order):
(4, 5)(7, 8), 
(3, 4)(6, 7), 
(2, 3)(4, 5), 
(1, 6, 7)(2, 5, 3), 
(1, 3, 8, 5, 7, 2)(4, 6)
orbits: { 1, 7, 2, 8, 6, 5, 3, 4 }

code no       2:
================
1 1 1 1 2 0 0 0
2 1 1 0 0 2 0 0
2 1 0 1 0 0 2 0
0 2 1 1 0 0 0 2
the automorphism group has order 24
and is strongly generated by the following 4 elements:
(
2 0 0 0 
0 2 0 0 
0 0 2 0 
0 2 1 1 
, 
1 0 0 0 
0 1 0 0 
0 0 0 1 
0 0 1 0 
, 
2 1 0 1 
0 0 0 1 
0 1 0 0 
0 0 2 0 
, 
1 1 1 1 
0 2 1 1 
0 0 0 1 
0 2 0 0 
)
acting on the columns of the generator matrix as follows (in order):
(4, 8)(5, 7), 
(3, 4)(6, 7), 
(1, 6, 7)(2, 3, 4), 
(1, 7, 6, 5)(2, 4, 3, 8)
orbits: { 1, 7, 5, 6 }, { 2, 4, 8, 3 }

code no       3:
================
1 1 1 1 2 0 0 0
2 1 1 0 0 2 0 0
1 2 0 1 0 0 2 0
2 2 1 1 0 0 0 2
the automorphism group has order 32
and is strongly generated by the following 5 elements:
(
2 0 0 0 
0 2 0 0 
2 1 0 2 
1 2 2 0 
, 
1 0 0 0 
0 1 0 0 
0 0 0 2 
0 0 2 0 
, 
0 1 0 0 
1 0 0 0 
2 1 1 0 
1 2 0 1 
, 
2 2 1 1 
2 2 2 2 
2 1 0 2 
0 0 0 1 
, 
0 0 2 0 
1 2 0 1 
1 0 0 0 
1 1 1 1 
)
acting on the columns of the generator matrix as follows (in order):
(3, 7)(4, 6), 
(3, 4)(5, 8)(6, 7), 
(1, 2)(3, 6)(4, 7), 
(1, 8)(2, 5)(3, 7), 
(1, 3)(2, 7)(4, 5)(6, 8)
orbits: { 1, 2, 8, 3, 5, 7, 6, 4 }