Creating an original graphical abstract for publishing can be challenging. You can use Mind the Graph (https://mindthegraph.com) to create and boost your work impact! Also, there are some guidelines in the blog that connect you with the necessary steps: https://mindthegraph.com/blog
Gaurav Kumar Singh, there are several alternatives to create graphical abstracts such as Cytospace, Gimp, ImageMagick, ImaheJ, Inkspace, and R. Some of these are basic and simple to use while others have more drawing tools and require more effort. Gimp and Inkscape, for example, are two good open-source, semi-professional programs. In any case, choosing one that will work for you will depend on your needs. You can find information, URLs, and tips on https://www.enago.com/academy/which-tools-should-you-use-to-design-quality-images-for-research-papers/.
You can use Inkscape. It is a free and open-source vector graphics editor for GNU/Linux, Windows and macOS X. It offers a rich set of features and is widely used for both artistic and technical illustrations such as cartoons, clip art, logos, typography, diagramming and flowcharting. It uses vector graphics to allow for sharp printouts and renderings at unlimited resolution and is not bound to a fixed number of pixels like raster graphics.
Go to: https://inkscape.org/
For editing Images and getting the desired output from Inkscape use
Gaurav Kumar Singh it depends on your skills, I recommend; PowerPoint, Inkscape, Photoshop, and Adobe Illustrators. You can also improve your graphical abstract by using other free online software: Biorender (https://biorender.com/), and Mid the graph (https://mindthegraph.com/).