---
- hosts: all_servers
vars:
ansible_python_interpreter: auto_legacy_silent
users:
- "user1"
- "user2"
- "user2"
tasks:
- name: "Ensure group admin exists"
group:
name: admin
state: present
- name: "Create user accounts"
user:
name: "{{ item }}"
groups: "admin"
shell: /bin/bash
with_items: "{{ users }}"
- name: "Add authorized keys"
authorized_key:
user: "{{ item }}"
key: "{{ lookup('file', 'files/'+ item + '.pub') }}"
with_items: "{{ users }}"
- name: "Allow admin users to sudo without a password"
lineinfile:
dest: "/etc/sudoers" # path: in version 2.3
state: "present"
regexp: "^%admin"
line: "%admin ALL=(ALL) NOPASSWD: ALL"

Create SSH user keys in files directory:

ssh-keygen -t rsa -f ~/files/user1.pub -C user1
ssh-keygen -t rsa -f ~/files/user2.pub -C user2
ssh-keygen -t rsa -f ~/files/user3.pub -C user3

Run ansible yaml:
ansible-playbook users_create.yaml

That will create 3 users in all_servers group with sudo privileges.