That chart is a bit different from the actual Saints fleur-de-lis.
What I would do is download knitters graph paper and draw the correct fleur-de-lis on it, then use it for designing an afghan around the motif. There's software you can use to create a close copy of anything. Check the hints on this page: http://domestikgoddess.com/3-easy-ways-to-chart-a-knitting-pattern/
Or if you're going to crochet the afghan, you can use single crochet and regular graph paper.
You could put a large fleur-de-lis in the center and small ones at the four corners. You could do just the center motif and then crochet a deep, deep border around the motif. You can get creative with the placement--the most important thing is the right colors and the right motif.
The knitted fleur-de-lis would be done as intarsia. Knit to the color change, drop the old color and pick up the new by twisting the new yarn around the old. This link from http://www.knittinghelp.com illustrates intarsia: http://www.knittinghelp.com/apps/flash/video_player/play/2/1
The crocheted one is a simple color change. Sc the background color to the first color change on your chart, pull the new color through as the last loop of the last sc of the background color, then sc the correct number of stitches in the first contrasting color (cc1). When you change colors, always make the color change on the last loop of the last sc in the old color.
Or do the center motif in Tunisian crochet/Afghan stitch and cross-stitch the fleur-de-lis motif on, using your chart to go by.