Using the action guielementHitTest, and get the touch coordinate on screen ( there is an action for this ), so you can test if the touch hit he guitexture, form there either you flag a bool ( using global var can be good if you control your player in anther fsm, or send an event.
for a game i am doing i went with separate Fsm to detect the guiTexture input then flag between 2 global variable, on my another Fsm for player control ( in my case i just rotate left or right ) the player fsm check for the global variable and drive to 2 event ( one for left , other for right)
while turning right or left then i still check the corresponding boolean var so when the Fsm that handle GUIHIt set it to a false state, i can then stop my rotation, back to the previous Fsm that listen for both global and so on
that's one way to do , but it is not really complicate setup to do...