The language that consists of the single string a x (including the space in the middle.)
The finite automaton that is the equivalent of the RE
a x has
a state transition for each character of the accepted string.
The middle transition is labeled ' ' to show a single space
Do not label a state transition with a string such as a x because a state transition consumes just one character each time it is followed. Label the transition to show what character is consumed. Often, a transition is labeled with several characters to choose from, but it only consumes one of them.
Can a space character be part of a string?