Source Code
set xrange [-2:2]
set yrange [-2:2]
set size square
set arrow 1 from cos(pi*0),sin(pi*0) to cos(pi*1/3),sin(pi*1/3) linewidth 1 linecolor rgb "red"
set arrow 2 from cos(pi*1/3),sin(pi*1/3) to cos(pi*2/3),sin(pi*2/3) linewidth 1 linecolor rgb "red"
set arrow 3 from cos(pi*2/3),sin(pi*2/3) to cos(pi*3/3),sin(pi*3/3) linewidth 1 linecolor rgb "cyan"
set arrow 4 from cos(pi*3/3),sin(pi*3/3) to cos(pi*4/3),sin(pi*4/3) linewidth 1 linecolor rgb "cyan"
set arrow 5 from cos(pi*4/3),sin(pi*4/3) to cos(pi*5/3),sin(pi*5/3) linewidth 1 linecolor rgb "green"
set arrow 6 from cos(pi*5/3),sin(pi*5/3) to cos(pi*6/3),sin(pi*6/3) linewidth 1 linecolor rgb "green"
set arrow 7 from cos(pi*0),sin(pi*0) to cos(pi*2/3),sin(pi*2/3) linewidth 4 linecolor rgb "red"
set arrow 8 from cos(pi*2/3),sin(pi*2/3) to cos(pi*4/3),sin(pi*4/3) linewidth 4 linecolor rgb "blue"
set arrow 9 from cos(pi*4/3),sin(pi*4/3) to cos(pi*6/3),sin(pi*6/3) linewidth 4 linecolor rgb "green"
set parametric
plot [0:2*pi] cos(t),sin(t) linewidth 4 linecolor rgb "purple"
replot cos(t)+cos(pi*0/3),sin(t)+sin(pi*0/3) linecolor rgb "orange"
replot cos(t)+cos(pi*1/3),sin(t)+sin(pi*1/3) linecolor rgb "orange"
replot cos(t)+cos(pi*2/3),sin(t)+sin(pi*2/3) linecolor rgb "orange"
replot cos(t)+cos(pi*3/3),sin(t)+sin(pi*3/3) linecolor rgb "orange"
replot cos(t)+cos(pi*4/3),sin(t)+sin(pi*4/3) linecolor rgb "orange"
replot cos(t)+cos(pi*5/3),sin(t)+sin(pi*5/3) linecolor rgb "orange"