InnerAutomorphisms( group )  
InnerAutomorphisms computes all the inner automorphisms of the group 
group. 
The inner automorphisms are returned as a list of transformations s.t. 
the identity automorphism is always the last entry in this list. For each  
transformation in this list the record components 
is-Inner-Auto-mor-phism, 
is-Group-En-do-mor-phism, 
and is-Group-Auto-mor-phism are all set to true.
  gap> i := InnerAutomorphisms( d8 );
  [ Transformation( Group( (1,2,3,4), (2,4) ), [ 1, 2, 8, 7, 5, 6, 4, 3 
       ] ), Transformation( Group( (1,2,3,4), (2,4) ), 
      [ 1, 5, 3, 7, 2, 6, 4, 8 ] ), Transformation( Group( (1,2,3,4), 
      (2,4) ), [ 1, 5, 8, 4, 2, 6, 7, 3 ] ), 
    Transformation( Group( (1,2,3,4), (2,4) ), [ 1, 2, 3, 4, 5, 6, 7, 8 
       ] ) ]
GAP 3.4.4