There are some differences due to the way each camera processed each image. Nikon's 'Standard' Picture Control is more neutral, while Canon's 'Standard' Picture Style is punched up with saturation, contrast, and sharpening. The closest Nikon equivalent of the Canon 'Standard' Picture Style is 'Vivid'. The Canon Picture Style closest to Nikon's 'Standard' is probably 'Faithful'.
But the main reason the Canon example looks more vibrant than the Nikon example is that there is more vibrant light illuminating the scene.
The Nikon example is shooting down onto relatively dark green leaves that are mostly shaded. The colorful butterfly is fairly small in the frame and the colorful bud of the flower is mostly hidden by flat green leaves.
The Canon example is composed in such a way that the most colorful parts of the scene take up a much larger portion of the frame and much of the background is illuminated by warm light, rather than in the shade.
If one looks critically at both examples, the butterfly is actually brighter and more colorful in the Nikon image! But it is so small in the frame that it is overwhelmed by the shaded green leaves. The Canon image, on the other hand, allows the butterfly and the flower to dominate the frame so that the colors force their way into our perception.