\begin{tikzpicture}[scale=0.4,every node/.style={transform shape}]
	\node [output_neuron] (out0) at (0,12)  {} ;

	\node (input0) at (-0.75,7)  {$x_1$};
	\node (input1) at (0.75,7) {$x_2$};
	\node (input2) at (2.25,7) {$x_3$};

	\node [hidden_neuron] (hi0) at (-4.5,10)  {  } ;
	\node [hidden_neuron] (hi1) at (-3,10)  {  } ;
	\node [hidden_neuron] (hi2) at (-1.5,10)  {  } ;
	\node [hidden_neuron] (hi3) at (0,10)  {  } ;
	\node [hidden_neuron] (hi4) at (1.5,10)  {  } ;
	\node [hidden_neuron] (hi5) at (3,10)  {  } ;
	\node [hidden_neuron] (hi6) at (4.5,10)  {  } ;
	\node [hidden_neuron] (hi7) at (6,10)  {  } ;



	\node (bias) at (-6,10)  {$bias=$-3} ;

	\node (output0) at (0,13)  {$y$} ;

	\node (w1) at (-2.8,11)  {$w_1$} ;
	\node (w2) at (-1.85,11)  {$w_2$} ;
	\node (w3) at (-1.0,11)  {$w_3$} ;
	\node (w3) at (-0.3,11)  {$w_4$} ;
	\node (w3) at (0.4,11)  {$w_5$} ;
	\node (w3) at (1.2,11)  {$w_6$} ;
	\node (w4) at (1.85,11)  {$w_7$} ;
	\node (w4) at (2.7,11)  {$w_8$} ;

	\draw [->,  red] (input0) -- (hi0);
	\draw [->,  red] (input1) -- (hi0);
	\draw [->,  red] (input2) -- (hi0);

	\draw [->,  red](input0) -- (hi1);
	\draw [->,  red](input1) -- (hi1);
	\draw [->,  blue] (input2) -- (hi1);

	\draw [->,  red] (input0) -- (hi2);
	\draw [->,  blue] (input1) -- (hi2);
	\draw [->,  red] (input2) -- (hi2);

	\draw [->,  red](input0) -- (hi3);
	\draw [->,  blue](input1) -- (hi3);
	\draw [->,  blue] (input2) -- (hi3);

	\draw [->,  blue](input0) -- (hi4);
	\draw [->,  red](input1) -- (hi4);
	\draw [->,  red] (input2) -- (hi4);

	\draw [->,  blue](input0) -- (hi5);
	\draw [->,  red](input1) -- (hi5);
	\draw [->,  blue] (input2) -- (hi5);

	\draw [->,  blue](input0) -- (hi6);
	\draw [->,  blue](input1) -- (hi6);
	\draw [->,  red] (input2) -- (hi6);

	\draw [->,  blue](input0) -- (hi7);
	\draw [->,  blue](input1) -- (hi7);
	\draw [->,  blue] (input2) -- (hi7);

	\draw [->] (hi0) -- (out0);
	\draw [->] (hi1) -- (out0);
	\draw [->] (hi2) -- (out0);
	\draw [->] (hi3) -- (out0);
	\draw [->] (hi4) -- (out0);
	\draw [->] (hi5) -- (out0);
	\draw [->] (hi6) -- (out0);
	\draw [->] (hi7) -- (out0);

	\draw [->] (out0) -- (output0);

	%\node at (-6,1) {red edge indicates $w$ = -1};
	%\node at (-6,0) {green edge indicates $w$ = +1};

\end{tikzpicture}
