How to render mesh in .ply with vertex color?

Question

I'm quite new to blender and I'm trying to render some meshes in .ply format shown below.

ply
format ascii 1.0
element vertex 470282
property float x
property float y
property float z
property uchar red
property uchar green
property uchar blue
element face 940612
property list uchar int vertex_index
end_header
x y z R G B
...
3 v1 v2 v3
...

This is what I tried so far and I can get the rendered image like 1st image but without any colors. What should I add in the python script so the rendered image has colors like the 2nd image(I was able to get this by changing to vertex paint in blender GUI but couldn't get the same image during rendering)? Would it be easier if I save the mesh in .obj format?

import bpy, sys, os
from math import pi

#remove
bpy.ops.object.mode_set(mode='OBJECT')
bpy.ops.object.select_all(action='DESELECT')
for this_obj in bpy.data.objects:
    if this_obj.type=="MESH":
        this_obj.select_set(True)
        bpy.ops.object.delete(use_global=False, confirm=False)

file_loc = 'path/to/mesh.ply'
imported_object = bpy.ops.import_mesh.ply(filepath=file_loc)

#load
for this_obj in bpy.data.objects:
    if this_obj.type=="MESH":
        this_obj.select_set(True)
        bpy.context.view_layer.objects.active = this_obj
        bpy.ops.object.mode_set(mode='EDIT')
        bpy.ops.mesh.split_normals()

bpy.ops.object.mode_set(mode='OBJECT')
# bpy.ops.object.mode_set(mode='VERTEX_PAINT')

# render
        
# rotate obj
bpy.context.object.rotation_euler[0] = pi / 2
bpy.context.object.rotation_euler[2] = -3 * pi / 4

# view - 1
cam = bpy.data.objects['Camera']
cam.location.x = -0.05
cam.location.y = -1.2
cam.location.z = 0.52
cam.rotation_euler[0] = 1.13446
cam.rotation_euler[1] = 0
cam.rotation_euler[2] = 0

bpy.context.scene.render.image_settings.color_mode = 'RGBA'
bpy.context.scene.render.filepath = 'path/to/render.png'
bpy.ops.render.render(write_still=True)