That appears to be a whole cloth quilt. There are tons of ways to mark a quilt but always do a sample first with whatever method to be sure the marks come out. There are quilt pens that come out with water spritzed over them. There are quilt pens that fade over time. There are chalk pump pens that was out.
There are chalk pounce pads and stencils.....
The next method would be a variety of papers that you stitch through. There is Goldenthread paper, paper designs already printed at some quilt shops, tissue paper patterns you make yourself......
Are you planning to hand quilt or machine quilt? It does make a difference on which method you can use depending on hand or machine.