Button Not reseting.,Button for pause and resume

I am trying to implement an in game pause play button which allows the user to pause the game when clicked once and resume when re clicked. I have used the transition type on the button as “Sprite swap”

When the button is clicked the game stops and the sprite changes to an image which says “resume” however when re clicked the game restarts but the sprite remains at the “Resume” image.
How do i make it go back to the pause image sprite??

I usually do this with 2 buttons or just 2 images.