The ornamental design for a displayscreen with a graphical user interface, as shown and described.
FIG. 1 is a front view of a first image in a sequence of a display screen with a graphical user interface showing the new design.
FIG. 2 is a second image thereof.
FIG. 3 is a third image thereof; and,
FIG. 4 is a fourth image thereof.
The appearance of the graphical user interface transitions sequentially between the images shown in FIGS. 1-4. The process or period in which one image transitions to another image forms no part of the claimed design.
The outermost broken lines illustrate a display screen and form no part of the claimed design. The dash-dot lines shown in the drawings represent an outer boundary of the claimed design and form no part of the claimed design. The remaining broken lines illustrate subject matter that forms no part of the claimed design.