Draw this circle with ellipse tool. Use #76AEF0 as fill color :
Apply these layer styles :
Select this layer by control+click on its layer's name in layer palette.
Create a new layer. Change the foreground and background colors to black & white by pressing 'D'. Now press 'x' to swap the colors. Use gradient tool (foreground to transparent) to fill this selection.
Press control+d to deselect. Control+J to copy and place this layer as shown :
Use pen tool to draw this shape :
Adjust the nodes as shown :
Use line tool
with 2 px weight
and draw the lines as shown. Our chat button is ready :)
